The Page class is associated with files that have an .aspx extension. These files are compiled at run time as Page objects and cached in server memory.

If you want to create a Web Forms page using the code-behind technique, derive from this class. Rapid application development (RAD) designers, such as Microsoft Visual Studio, automatically use this model to create Web Forms pages.

The Page object serves as the naming container for all server controls in a page, except those that implement the INamingContainer interface or are child controls of controls that implement this interface.

The following code example demonstrates how the Page class is used in the code-behind page model. Note that the code-behind source file declares a partial class that inherits from a base page class. The base page class can be Page, or it can be another class that derives from Page. Furthermore, note that the partial class allows the code-behind file to use controls defined on the page without the need to define them as field members.

The following code example shows the .aspx file that corresponds to the preceding code-behind source file.

Security Note:

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

You must use the @ Page directive and use the Inherits and CodeFile attributes to link the code-behind file to the .aspx file. In this example, the Inherits attribute indicates the MyCodeBehind class and the CodeFile attribute indicates the path to the language-specific file that contains the class.

The following code example demonstrates the single-file page model and how to access the IsPostBack property and the Response property of the Page.